Apparatus for separating stem portions from disintegrated tobacco mass



March 5, 1957 E. R. DAHLSTRC'DM ET AL 2,783,888 APPARATUS FOR SEPARATINGSTEM PORTIONS FROM DISINTEGRATED TOBACCO MASS Filed April 6, 1954 INVENTORS E.R. DAHLSTROM .C. 6; 3-. ROTHELIUS APPARATUS FOR SEPARATING STEMPORTIONS FROM DISINTEGRATED TOBACCO MASS Ernst Ruben Dahlstriim, Alsten,and Carl Georg Bertil Rothelius, Stockholm, Sweden, assignors to ArencoAktiebolag, Stockholm, Sweden, a Swedish joint-stock company ApplicationApril 6, 1954, Serial No. 421,345 Claims priority, application SwedenApril 29, 1953 4 Claims. (Cl. 209-295) This invention relates toapparatus for separating stem portions from disintegrated tobacco massand more particularly to an apparatus of that kind provided with anendless sieve, e. g. a drum or band, and stripper means for removingimpurities and waste from the surface of said sieve. It is an object ofthe invention to prevent tobacco leaf fragments, adhering by suction tothe sieve, from following the impurities and waste all the way to thestripper means which would cause losses of tobacco if said leaffragments are to be removed together with the waste. Another object ofthe invention is to prevent contamination of the cleaned tobacco whichwould be the result if leaf fragments removed by the stripper meanswould be returned to the tobacco mass together with the waste.

These and other objects and advantages of the invention will in part bedescribed and in part be understood from the following detaileddescription of a preferred embodiment, which is illustrated in theaccompanying drawing.

Referring to the drawing, disintegrated tobacco mass is supplied to ajigger 2 which delivers the tobacco through an opening 3 into a verticalseparating channel 4, in which an ascending air current elevates therelatively light tobacco leaf fragments while the relatively heavy stemportions are allowed to sink down in the channel and further through abottom opening 5 into a receptacle 6. The leaf fragments follow the aircurrent out of the outlet opening 7 of the horizontal portion 4a of theseparating channel 4 and enter a relatively large chamber 8 in which theleaf fragments sink down, whereafter they are removed through a rotarysluice 9 in the bottom of the chamber.

A continuously revolving sieve drum 10 is positioned in the upperportion of the chamber 8 opposite to the opening 7. The drum 10 may beperforated or it may consist of wire network. Close by the inner surfaceof the drum 10 and concentrically thereto is positioned a stationarytubular shield 11 which has perforations in its front portion only, i.e. in the portion turned towards the outlet opening 7 of the separatingchannel 4. Right behind or at least approximately right behind the rearside of the shield 11 is a stripper roll 13 mounted rotatably. The roll13 has longitudinal fillets or lamellae 25 of a soft material, e. g.leather, which beat upon the sieve drum 18 when the roll 13 rotates.

A plate 14 extends obliquely from the sieve drum 10 down to the rearwall 15 of the chamber 8. The upper edge 22 of the plate 14 ispositioned close by the sieve drum 1G in the proximity of the rearvertical plane of tangency of the drum. The plate 14 forms one of thewalls of a pocket 16 closed at its bottom and having a collecting box ordrawer 17 inserted therein. The drawer 17 can be pulled out of thepocket 16 through a normally closed opening 18 in one of the side wallsof the chamber 8. The ends of the sieve drum 10 are located close by theside walls of the chamber 8 and it is at one of 2 said walls or at boththe walls connected to a conduit 23 which over a dust separator (notshown) is connected to the suctionsid'e of afan 20. The pressure side ofthe fan 201s through; a conduit 24'tightly connected to the receptacle6.--

Intheopera'tion ofthe apparatus the sieve. drum 10 and the stripperrol-l13*are-rotated in the directions as shown in the drawing. Air flowingout of the outlet opening 7 of the channel 4 will mainly find its waysubstantially directly to the portion of the sieve drum 10 covering theperforations 12 of the shield 11 where dust is sucked in through saidperforations and coarser impurities such as fibrous particles willadhere by suction to the drum and follow same in its rotary directionuntil they reach the roll 13 which is beating against the sieve drum sothat the impurities are removed therefrom and drop into the box 17 inthe pocket 14. The suction effect on the leaf fragments thatadhere tothe drum 10 opposite to the perforations 12 of the shield 11 and followthe drum against the stripper roll 13 is cording as they approach saidroll. The air gap 21 between the shield 11 and the drum 10 is so thinthat the peripheral air currents in same are choked. The suction effecton the rear side of the sieve drum 10, turned towards the rear wall 15of the chamber 8, is so feeble that no leaf fragments or a few fragmentsonly will be sucked through the passage between the top portion of thedrum 10 and the top wall of the chamber 8. Leaf fragments that do notleave the drum 10 until they reach the plate 14 may be stripped off thedrum by means of the upper edge 22 of said plate. Fibrous and mattedimpurities will stick more firmly to the drum 10 than the leaf fragmentsbut when they have reached the roll 13 they are in a zone in which thesuction effect is a minimum wherefore the roll 13 will be capable ofloosening them from the drum.

We claim:

1. In an apparatus for separating stem portions from a disintegratedtobacco mass, an endless sieve, a stem separating channel heaving anoutlet for cleaned tobacco leaf portions located opposite to said sieve,a stationary shield located closely inside said sieve and conforming toSaid sieve and having an air inlet only in a-front side opposite to saidchannel outlet, said sieve being mounted for rotation over said airinlet, a suction conduit connected to the interior of said shield, andstripper means located at the rear side of said sieve and operativelyassociated with said sieve to remove waste therefrom.

2. In an apparatus for separating stem portions from a disintegratedtobacco mass, an endless sieve, a stem separating channel having anoutlet for cleaned tobacco leaf portions located opposite to said sieve,a stationary shield located closely inside said sieve and conforming tosaid sieve and having an air inlet only in a front side opposite to saidchannel outlet, said sieve being mounted for rotation over said airinlet, a suction conduit connected to the interior of said shield, aroll having leather lamellae and being located at the rear side of saidsieve, and said roll being mounted for rotation to cause its lamellae tobeat on said sieve and remove waste therefrom.

3. In an apparatus for separating stem portions from a disintegratedtobacco mass, an endless sieve, a stem separating channel having anoutlet for cleaned tobacco leaf portions located opposite to said sieve,a stationary shield located closely inside said sieve and conforming tosaid sieve and having an air inlet only in a front side opposite to saidchannel outlet, said sieve being mounted for rotation over said airinlet, a suction conduit connected to the interior of said shield,stripper means located at the rear side of said sieve and operativelyassociated with said sieve to remove waste therefrom, and a wastecollecting pocket below said stripper means, said pocket decreasedsuccessively achaving a downwardly extending wall having an upper'nected to the interior of said shield, a roll having longiedgelocatedclose by the rear portion of said sieve below said stripper n1eans. V

4. In an apparatus for separating stem portions from a disintegratedtobacco mass, an endlesssievega stern separating channel having anoutlet for cleaned tobacco leaf portions located opposite to said sieve,a stationary shield located closely inside said sieve and conforming tosaid sieve and having an air inlet only in'a 'front side opposite tosaid channel outlet, said sieve being mounted for rotation over said airinlet, a suction conduit contudinal filletsflof a soft material andbeing located at the rear side of said sieve, and said roll beingmounted for rotation to cause said fillets to beat on said sieve andremove waste therefrom.

References Cited in the file of this patent FOREIGN PATENTS

